Multiple table drive



R. TYLER I MULTIPLE TABLE DRIVE Filed July so, 1942 Nov. 5, l lfi.

7 Sheets-Sheet 1 Ls34l3 INVENTO "ANSUM TYLER Nov. 5, 1946.

R. TYLE'R MULTIPLE TABLE DRIVE Filed July 30, 1942 7 Sheets-Sheet 2 III,IIIIIIIIIIII IYIIII 'llltllllllllllllllllllIll] mv em 'oR HANSU-M TYLER Wk. A onnzy. I

, NW. 5, W46. R. TYLER MULTIPLE TABLE DRIVE Filed July 30,-}942 '7 Sheets-Sheet 3 BNVENTOR RANsm i TYLER ma ma NW. 5, 1%.46. R. TYLER MULTIPLE TABLE DRIVE Filed July 30, 1942 7 Sheets-Sheet 4 Pym;

UNVENTOR HANSBM T YLER A ORNEY- Ollll.

Ollul R. TYLER MULTIPLE TABLE DRIVE Filed July so, 1942 7 sheets Sheet 5 INVENT' HANsuM TYLER NW. 5, am. R. TYLER 2mm HULTIPLE TABLE DRIVE Fil ed July so, 1942 7 Shets-Sheet, a

INVENTOR H AN 3 u M T YL ER NW 5,; 11%. R LE mmm MULTIPLE TABLE DRIVE To pre 55 a operating circuit mvawggfi I. ANSDM i YLER Patented Nov. 5, 1946 EIULTIPLE DRIVE Ransom Tyler, Greenfield, Wia, assignor to The Oilgear Company, Milwaukee,

tion of Wisconsin Wis., a corpora- Application July 30, 1942, Serial No. 452,924:

1 Claims. This invention relates to drives of the type employed for advancing and retracting a plurality of tables or slides in selective sequences.

For the purpose of illustration, the invention will be explained as employed for driving a plurality of tables associated with a hydraulic press but it is to be understood that a drive constructed according to the invention may be employed for other purposes.

Large hydraulic presses are sometimes provided with a plurality oftables or Work slides which are arranged around the outside of the press and are adapted to be moved one at a time into and out of the press so that operators may load work upon the tables outside the press during the time that the press is operating upon the work on the table which has been advanced into the press.

Since the time required to arrange the work in position for pressing is ordinarily considerably longer than the time required for the pressing operation, approximately as much work can be performed upon a press having, for example, four tables as can be performed upon four single table presses.

In some instances, the tables are moved into and out of the press in a fixed sequence but,

multiple table presses are ordinarily employed for operating upon many different types of work, the timerequired to load one table may be only a small fraction of the time required to load another table in which case the production capacity of the press is greatly reduced if the The present invention has as an object to provide a multiple table press with a drive of such character that the operators who load the tables may control the movements of the tables into and out of the press to therebyeliminate the necessity of employing an additional operator.

Another object is to provide a drive of this character in which each operator may operate a control to initiate movement of his table into and out of the press but that table will not move until the table in the press has been fully retracted therefrom.

another obj act is to provide a drive of this character in which the tables will move into andout- 2 of the press in the order in which the controls of the several tables are operated.

Another object is to provide a drive whic will accelerate and decelerate eachtable at a rate-slow enough to avoid displacing work arranged upon the table.

Other objects and advantages will appear from the following description of a multiple table press having a drive embodying the invention and shown schematically in the accompanying drawings in which the views are as follows: 7

Fig. 1 is a diagrammatic'front view of a multiple table press provided with a table drive constructed according to the invention.

Fig. 2 is a sectional plan view taken on the line 2-2 of Fig. 1.

Fig. 3 is a diagram of the hydraulic circuit and shows the solenoids for operating the pilot and control valves.

Figs. 4 and 5 are views showing the pilot valve with its plunger in positions diiierent from that shown in Fig.3.

Fig. 6 is a diagram showing the magnetic switches for controlling the operating solenoids shown in Fig. 3.

Figs. '7 and 8 are diagrams showing relays or contactor switches .for controlling the magnetic switches shown in Fig.6.

'Figs. 9 and 10 are across-the-line diagrams which together show the complete control cir= cuit.

For the purpose of illustration, a drive embodying theinvention has been shown applied to a press having four tables or work slides i, 2', 3, and t but the invention may readily be applied to a press having a difierent number of tables.

As shown, the press includes a lied 5, a head frame 5 connected to bed 5 by four strain rods i, a ram cylinder a carried by head 6 and a ram a fitted in cylinder a and connected to a platen it which is slidable upon and guided by rods l. Tables i, 2, 3 and i when outside the press are arranged, respectively, upon supports ii, i2, i3

and it which are arranged around bed 5 and have their upper surfaces flush with the upper surface of bed 5 so that they may be advanced one at a time onto bed 5 and beneath a rubber p d i5 carried by platen id upon the underside thereof.

At least one operator is provided for each table, dies (not shown) are arranged upon the table: and work is arranged upon the dies. When any one of the tables with work thereon is advanced into the press, ram Q will advance platen it; and. cause pad to operate upon the work on that table until the pressing operation is completed and then ram 9 will automatically retract platen I II to and stop it in its upper position.

ihe press is provided with a suitable power plant for operating it and with a suitable control for causing it to operate semi-automatically as explained above but, since the press per se forms no part of the present invention, the power plant and pressqcontrol have been omitted from the drawings and only so much of the press shown as is necessary for an explanation of the inven tion.

Tables I, 2, 3 and 4 are operated, respectively, byreciprocating hydraulic motors M1, M2, M3 and M4 each consisting of a cylinder l5 (Fig. 3) and a piston I1 which is fitted in cylinder 16 and connected by a rod 18 to the inner end of the table as shown in dotted lines in Fig. l, the movem mi; of each table in each'direction being limited by a positive stop, not shown.

the table motors are energized by liquid supplied thereto from a pump 20 which may be reversible to direct liquid into one and receive liquid from the other of two channels 2| and 22 or it may 'be of the unidirectional type and a reversing valve provided to reverse the direction of flow. For the purpose of illustration, pump 29 has beenshown as bein reversible and of the rolling piston type. Since this type of pump is fully illustrated and described in Patent No. 2,047,068, it is deemed suflicient to state herein that pump 29 has itslpumping mechanism arranged within a displacement varying member or 29 is zero and no liquid will he delivered thereby.

Slide block 23 is at all times urged toward the left by liquid acting upon a piston 24 connected to or in engagement with slide block 23 and fitted in a stationary cylinder 25 which is carried by the casing of pump 20 and has an adjusting screw 25 4 Pistons 21 and 23 are larger than piston 24 so that slideblock 23 will be moved toward the right when liquid is simultaneously supplied to both of cylinders 25 and 29 at the same pressure. Liquid for operating pistons 24, 21 and 23 is supplied by a gear pump 35 which is ordinarily 31 at a rate in excess of requirements, the excess liquid being exhausted through a relief valve 38 which enables gear pump 35 to maintain in channel 31 a pressure equal to the resistance of relief valve 33.

One branch of supply channel 31 is connected to the outer end of cylinder 25 so that piston 24 is constantly urged toward the left by a constant force which is proportional to gear pump pressure. This branch has an adjustable choke 39 arranged therein to limit the rate of flow to and from cylinder 25 and thereby limit the rate at which pistons 24, 21 and 28 can shift slide block 23.

Another branch of supply channel 31 is connected to a Pilot valve 40 which controls the flow of liquid to and from,cylinder 29 and thereby controls the operation of pump 29. Pilot valve 40 has a valve member or plunger 41 fitted in a valve casing 42 to control communication between four annular grooves or ports 43,-, and 46 formed in valve casing 42. v I

Port 43 communicates with the branch of supply channel 31 that is connected to valve 40. Port 44 is connected by a channel 41 to cylinder 29 at Or near the outer end thereof. Port 45 is threaded through its outer end to limit the movement of piston 24 and slide block 23 toward the right. Turning screw 25 will a just the rate at which pump 20 will discharge liquid into channel 2 I.

.Slide block 23 is adapted to be moved toward the right by liquidacting upon one or the other of two pistons 21 and 28 which are fitted in a stationary cylinder 29 carried by the pump casing. Piston 21 engages slide block 23 and piston 28 is adapted to engage .the outer face of piston 21.

The movement of piston 28 toward the right is limited by a collar 39 fixed on a stop rod 3| which extends loosely through pistons 21 and-28 and through the head of cylinder 29. The inner end of rod 31 is adapted to engage slide block 23 and the outer end of rod 31 is provided with a nut 32 which, in the present instance, is adjusted to so position collar 30 that piston 28 when energized will move slide block 23 to a position just short of neutral so that pump 20 will at that time deliver liquid into channel 22 at a rate which is very limited, such as two or three percent of maximum.

The outer end of rod 31 is adapted to engage an adjusting screw 33 which is threaded through a cap 34 fixed to the head of cylinder 29. Turning screw 33 adjusts the distance rod 3| and slide block 23 may be moved toward the left to thereby determine the rate at which pump 20 will deliver liquid into channel 22.

connected by a channel 48 to cylinder 29 at, a point between pistons 21 and 28. Port 46 is connected' to a drain channel 49 which discharges into reservoir 36.

Valve member 4| is urged to and normally retained in its central or neutral position by two springs 4| and 41 which are arranged in suitable spring chambers located at opposite endsof casing 42. Valve member 4| is adapted to be shifted in one direction or the other by one or the other of two solenoids S5 and $6 the armatures of which are connected to opposite ends of valve 7 member 4! by suitable valve stems.

Due to the displacement of each piston rod 18, the volume discharged by pump 20 will vary from the volume discharged from any one of the motors by an amount equal to the displacement of rod 18. It is therefore necessary to supply liquid from reservoir 33 to pump 20 during movement of a piston l1 in one direction and to permit the discharge of liquid into reservoir 36 during movement of a piston I1 in the opposite direction. This is accomplished by providing pump 23 with an automatic valve 52 which is arranged in a bore 53 having two annular grooves or ports 54 and 55 formed in the wall thereof. Port 54 and the left end of bore 53 are connected to channel 2l by a channel 2 l port 55 and the right v but prevents the discharge of liquid from bore 53 except through resistance valve 51.v

The delivery of liquid from'pump 20 o the head ends of the four table motors Ml, M2, M8 and M6 is controlled, respectively, by four normally closed control valves Vi, V2, V3 and V4 each of which includesa valve member 53 ar-.

ranged in a casing 69 and urged to its closed position by a spring 6'0. Valve member 58 controls communication between a branch of channel 22 and a channel 6| which connects casing 59 to the head end of cylinder i6. v

As will'presently appear, the rod ends of all four motors are supplied with-pressure liquid during the time any one motor is performing a cycle of'operation. Since the pressure in the end of a non-operating motor might cause liquid to leak past piston ll of that motor and cause it to creep ahead, each valve member 58 also controls communication between a'channel ti and a drain channel 69 which connects the casings of all four control valves to reservoir 35 but which has been omitted from the drawings in order to avoid complicating the view. When a control valve is open, its valve member 58 blocks communication between channel Bi anddrain channel is and connects channel iii to channel 22 so that motive liquid may flow to and from cylinder [6 to effect operation of piston i1 and, when a control valve is closed, the branch of channel 22 connected thereto is blocked by valve member 58 and channel 6! is open to drain channel 29 so that liquid can escape freely from the head end of cylinder i6 and thereby enable pressure in the rod end of cylinder I6 to return piston ii to and hold it firmly in its control valve.

When a piston ii is advanced by liquid supplied to the head end of its cylinder it, the

liquid discharged from the rod end of that cylinder i6 is directed to the head end thereof through a difi'erential valve which includes a casing 63 and a piston 6i fitted therein. Casing 63 has channels 2i and 22 connected to opposite ends thereof and it is connected intermediate its ends by a branched channel 65 to the rod ends of all four cylinders it. i

As shown in Fig. 2, each of tables I, 2, 3 and Q in its inward and outward movements operates four limit switches which have been indicated, respectively, by placing the digits 1, 2, 3 and 4 after the table reference numerals which are preceded by the letters LS. Ifhat is, table i operates limit switches LSH, LSI2, LSi3 and mi l, table2; operates limit switches 152i, L822, 1523 and LSZt, table 3 operates limit switches L336,

L332, L833 and 153%, and table operates limit switches LSM, L532, 15% and LS-fii l.

Limit switches LS! i, LSZi, LS3! and LSM are operated at the outer limits of table movement, switches LSi2, L822, LS32 and L822 are operated during outward table movement, switches LSit, LS2%, LSS and lists are operated during inward table movement, and switches LSiQ, Isfid,

' L53 and LSfit are operated at the inner limits of table movement. A limit switch LS5 is operated at or near the upper limit of platen iii and another limit switch 15% is operated du ing upward movement of platen III as shown in Fig. 1.

The actual mechanisms for operating the limit switches, the mountings therefor and the exact locations thereof have not been illustrated since they form no part of the invention and since the limit switches are necessarily shown on a much larger scale than the press structure. For example, the tables have been shown as relatively short and as having short strokes while in practice the table stroke is sometimes more than six feet. 1

Solenoid S5 and a control valve solenoid Si, S2, S3 or $5 are energized simultaneously as will presently be explained. Energizing a control valve solenoid causes it to open its control valve Vi, V2, V3 and Vt. Energizing solenoid S5 causes it to shift plunger ti of pilot valve to to the position shown in Fig. e to connect channels t1 and. 53 to drain channel d9 so that gear pump liquid can flow through channel 31 to cylinder 25 and cause piston is to'move slide block 23 slowly toward the left atthe rate determined by choke 39.

Moving slide block 23 22 and this liquid will tend to flow through channel 22 to reservoir 36 but, due to the resistance flow through channel 22 and the'open control valve to the head end of the table motor Mi. M2, M3 o'rMt associated with the open valve,-

thereby causing pump pressure to increase and shift difierential valve piston 65 toward the left so that pump pressure can extend through channel at to the rod ends of all four motors. If the pistons ll of the other motors have crept forward, the pressure in the rod ends of those -motcrs will return those pistons to their fully retracted positions for the reason that the head ends of those motors are open to drain through the closed control valves.

The liquid delivered by pump 20 to the head end of the motor Mi, M2, M3 or M6 will cause its piston H to advance the table i, 2, 3 or door:- nectedthereto, and the liquid expelled by piston H from cylinder iG will flow through channel 65 and diiferential valve casing 63 into channel 22 so that pump 20 need supply only a volume of liquid proportional to the area of rod it, the area of the rod ordinarily being nearly one half that of the piston so that the table is moved at nearly the same speed in both directions.

Due to the action of choke 29, slide block 2% moves slowly toward the left and gradually increases the displacement and volumetric delivery of pump 28 so that the table motor starts the table at a very slow speed and gradually. accelerates it to full speed. The table will continue to move, inward at full speed until it operates limit switch LSi, L823, L835 or 1.8% which will cause solenoid S5 to he deenergized as will presently be explained.

Deenergizing solenoid Si: permits spring ti to shift plunger it of pilot valve 65 to its neutral position and then gear pump liquid will flow through the channel 5.? to cylinder 2% and cause piston 28 to move slide block 22 nearly to its neutral position. Due to the action of choice 32$, slide block 27 will move slowly and thereby slowtoward the leftwill cause pump 20 to discharge liquid into channel i press.

ly decrease the displacement and volumetric delivery of pump 20 so that the speed of the inward moving table is gradually reduced until it reaches its inner limit and engages a positive stop (not shown) at which time pump delivery will have been reduced to the verylimited rate previously mentioned and then pump 20 will discharge through the relief valve (not shown) eration is completed and to then retract platen "I. As platen r, Ill approaches its upper limit, limit switch LS is operated to energize solenoid S3 which will shift plunger 4! of pilot valve 40 to the position shown in Fig. 5 and then gear pump liquid'will flow through channel 48 andcause piston 21 to shift slide block 23 toward the 25 right from its neutral position which will cause pump 20 to discharge liquid into channel 2|.

Resistance valve 51 will prevent pump 20 from discharging into reservoir 36 except at a low pressure and this pressure will extend through channel 2| tothe left end of bore 53 and shift valve 52 toward the right to the position shown to uncover port 55 and to block port 54 so that pump 20 can draw liquid freely from reservoir 36 through channel 22 but cannot discharge liquid into reservoir 36 through channel 2!.

The liquid discharged by pump 20 will'then flow through channel 2| to differential valve casing 63, shift piston 84 toward the right to the position shown and then flow through channel 65 to the rod end of the table motor and cause its piston I! to retract the table that is in the The liquid expelled fromthe head end of cylinder l6 by piston I1 is considerably in excess of the liquid required to supply pump 20, and the excess liquid is discharged through channel 22, port 55, bore 53 and resistance valve 31 into reservoir 35. I

Due to the action of choke 39, slide block 23 will move slowly and thereby cause the table to be started slowly and gradually accelerated to full speed as previously explained. The table will continue to move at full speed until it operates limit switch LSI2, L822, L832 orLS42 to cause solenoid S6 to be deenergized and thereby permit spring 4| to shift plunger 4| of pilot valve to its neutral position to connect pipe 48 to drain so that gear pump liquid may flow to'cylinder 25' and cause piston 24 to moveslide block 23 toward the left until it is stopped by piston 21 engaging piston 28 at which time slide block 23 is nearly in its neutral position and the delivery of pump 2|) is reduced to the very limited rate previously mentioned, choke 39 limiting the speed of slide block 23 and thereby causing the table to be gradually decelerated switches a, b, c, and ii and a magnet e for operating those switches. Solenoid S8 is controlled by a magnetic switch or contactor C6 which includesh eight mechanically connected switches a, b, c, d, e, f, g and h and a magnet i for operating those switches. I J

Magnet 1 of contactor 06 may be energized to effect reversal of a table by closing a manually operable reversing switch four of which are provided and associated, respectively, with tables I, 2, 3 and 4 but all of these reversing switches are rendered inoperative by any one of limit switches 15, L824, L834 and L844 being closed by a table reaching its inner position.

Magnets f of contactors Cl, C2, C3 and C4 are controlled in part by magnetic switches or relays RI, R2, R3 and R4 respectively. As shown .in Fig. 7, each of these relays include six mechanically connected switches a, b, c, d, e and jand a 20 magnet g for operating those switches. Magnet '9 of the relays are initially energized, respectively, by means of manually operable starting switches SSE, SS2, SS3 .and S34. A fifth relay R5 (Fig. 8) also includes six mechanically connected switches a, b, c, d, e and f and a magnet g for operating those switches. The circuit also includes four groups of interlocking switches or relays RI i, RZI and MI, RI2, R22 and R32, RI3,- R23 and R33 and RM, R24 and R34. Each of these relays includes two mechanically connected switches a and b and a magnet c for operating those switches as shown in Fig. 8.

The magnets and individual switches of the several contactors and relays have been .indicated in Figs. 9 and 10 and will be hereinafter referredto by reference characters produced by adding the reference letters of the magnets and switches as exponents to the reference characters of the contactors and relays. For example,

40 the switches and magnets of relay R34 are designated R34", R34 and R34 respectively.

As shown in Fig. 6, current for energizing the several solenoids is supplied from power lines Li and L2 which areconnected to a source of winding connected to line L4 and the second end of its winding connectable through a wire 12, the upper pair of contacts of limit switch LSI I and a wire 13 to line L3. The second end of the winding is also connectable through a wire [4, switch RI, 9. wire 15, switch Ri I, a wire 16, switch R21 a. wire 11, switch R3", 9. wire I8, switch R5 and a wire 19 to line L3.

Magnet 02 has one end of its winding connected to line L6 and the second end of its wind- 55 ing connectable through a wire 12, the upper pair of contacts of limit switch LSZI and a wire 13 to line L3. The second end of the winding is also connectable through a wire 14, switch R2, 2. wire 15*, switch Ri'i a wire it, swith R22 a wire H switch R32, 9. wire 13*, switch R5 and a wire i9 to lineL3.

Magnet C3 has one end of its winding connected to line L4 and the second end of its winding connectable through a wire 12, the upper pair of contacts of limit switch LS3I and wire [3 to line L3. The second end of the. winding is also con- ,nectable through a wire 14,- switch R3, awire 15 switch RI 3, a wire 18", switch R23, a wire 11 switch R33, a wire 18', switch R59 and a wire 13 to line L3. f

. Magnet C4 has one end of its winding connected to line L4 and the second end of its winding connectable through a wire 12, the upper pair of contacts of limit switch LS4I and wire 13 to line -L3. The second end of the winding is also connectable through a wire 14, switch R4, a wire 15, switch RIP, a wire 16'", switch R24", a wire 11, switch R34, a wire 18, switch R5 and a wire 19 to line L3.

Magnet C5 has one end of its winding connected to line L4 and the second end thereof connectable through a wire 80, switch R5 a wire 8I any one ofswitches CI, C2 C3 and 04, 2. wire 82. switch C8 and a wire 83 to line L3. Wire 82 is also connectable through a wire 84, limit switch LS5, a wire 85 and any one of limit switches LSI4, 1.824, L534 and L844 to the operating circuit of the press. The second end of the winding of magnet C8 is also connectable through switch C5, a wire 88, limit switches LSI3, L823, L533 and L543 which are in-series, and a wire 81 to wire 82 and thence through sw tch C8 and wire 83 to line L3.

Magnet has one end of its winding connected to line L4 and a second end thereof connectable through a wire 88, limit switches LSI4, L824, L834 and LS44 which are in series, wire 89 and any one of reversing switches RSI, RS2, RS3 and RS4 to line L3. The second end .of the winding of magnet C8 is also connected by a wire 90 to one terminal of switches C8 and C59. The second terminal of switch C3 is connectable through a wire 9|, any one of limit switches LSI2, L822, 1532 and L842 and a wire 92 to line L3, and the second terminal of switch is connectable through a wire 33, limit switch'LSB and a wire 92 to line L3.

Magnet R5 (Figs. 8 and has one end of its winding connected to line L4 and the other end thereof connectable through a wire 94, switch C4, a wire 95', switch C3, a wire 96, switch C2, a wire 91, switch CI, a wire 98 and limit switches 1SII,LS2I,LS3I andLS4ItolineL3. -The second end of the winding is also connectable through switch R5 and a wire 93 to wire 98.

Magnet RI (Figs. 7 and 9) has one end of its winding connected to line L4 and the other end a wire In to line 1.3. The other terminal of switch R3! is connectable through a wire. 102

switch C8 and a wire I03 to line L3 and through a wire I04 switch C3 and wire I05 to line L3.,

switch R4 is connectable through a wire .I02,

switch 00' and a wire )3 to line L3, and through nected to line L4 and the other end thereof connected to one terminal of switch R2 I and connected through a wire 2- to one terminal of switch R3. The other terminals of switches R2I and R3 are both connected by a wire II3 to the terminal of switch RI to which wire III is connected.

Magnet Rtl has one end of its winding connected to line L4 and the other end thereof connected to-one terminal-of switch Riil and connected through a wire II4 to one terminal of switch R4. The other terminals of switches R3I" and R4 are both connected by a wire II5 to the terminal of switch RI to which wires III and H3 are connected. The other terminal of switch RI is connected by wire I I6 to line L3.

Magnet RI2 has one end of its winding connected to line L4 and the other end thereof conthereof connected through a wire I00 to one terminal of switch RI and to one terminal of' starting switch SSI the other terminal of which is connected by a wire IOI to line L3. The other terminal of switch RI is connectablethrough a wire I02, switch 06 and a wire I03 toline L3 and through a wire I04, switch CI and a wire I05 to line L3. f

Magnet R2 has one-end of its winding connected to line L4 and the other end thereof connected through a wire I00 to one terminal of switch R2 and to one terminal of starting switch RI2 and RI are both connected by awire II I to one terminal of switch R2. Magnet R22= has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch R22 and connected through afwire 2" to one terminal of switch R3. The other terminals of switches R22 and R3 are both connected by a wire II3 t0 the terminal of switch R2 to which wire I I I is connected.

Magnet R32 has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch R32" and connected through a wire 4 to one terminal of switch R4. The other terminals of switches R32 and R4 are both connected by a wire H5 to the terminal of switch R2 to which wires I I I and II3 are connected. The other terminal of switch R2 is connected by a wire II 5' to line 1L3 Magnet RI 3 has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch RI3 and connected through a wire H0 to one terminal of switch RI. The other terminals of switches Ri3 and RI are both connected by a wire ill to one terminal of switch R3. Magnet R23= has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch R23 and connected through a'wire H2 to one terminal of switch R2". The other terminals of switches R23 and R2 are both connected by wire H3 to the terminal of switc R3 to which, wire 5 li is connected.

v 2,41o,ee4

- .Magnet R33 has one end of.its winding connected to line L4 and the other end thereof connected to.one terminal of switch R33 and connected through a wire II4 to one terminal of switch R4. The other terminals of switches R33 and R4 are both. connected by a wire II to the terminal of switch R3 to which wires 'I II and I I3 are connected. The other terminal of switch R3 is connectedby a wire IIIi to line L3.

Magnet RI4 has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch RM and connected through a wire 0 to one terminal of switch RI. The other terminals of switches R I4 and RI are both connected by a wire III to one terminal of switch R4 Magnet R24 has one end of its winding. connected to-line L4 and the other endthereof connected to one terminal of switch R24 and connected through a wire 2 to one terminal of switch R2. The other terminals of switches R24 and R2 are both connected by a wire I I 3 to the terminal of switch R4 to which wire I II is connected.

Magnet R34 has one end of its winding connected to line L4 and the other end thereof connected to one terminal of switch R34 and connected through a wire I I4 to one terminal of switch R3. The other terminals of switches R34 and R3 are both connected by a wire "5 to the terminal of switch R4 to which wires I I I and II3 are connected. The other terminal of switch R4 is connected by a wire I IB to line L3.

Operation 4 Assuming that the several parts are in the positions shown and that pumps 20 and 35 are running, the drive will operate as follows:

Line switch III (Fig. 6) is first closed to connect lines LI and L2 directly to the source of power and to connect lines L3 and L4 to the source of power through transformer II. Thi establishes, as shown in Fig. 10, a circuit (LL-R5 84- 04 i'I5C3 9B C2 91 GI -98- LSI I-LS2I--LS3ILS4I-L4) to energize magnet RS' which will raise relay R5 (Fig. 8) to close the switches a, b, c, d, e and 1 thereof. Closing switch R5 establishes a circuit (L4R5 -R5 99-98-LSIILS2I1S3I-IS4IL3) to keep magnet RS energized when any one of switches CI", C2, C3 or 04 open.

Let it now be assumed that table 2 has been loaded, that starting switch SS2 has been closed and that tables 4, I and 3 were loaded and starting switches SS4, SSI and SS3 were successively closed after switch SS2 was closed.

As shown in Fig. 9, closing switch SS2 establishes a circuit (L4R2 I00 -SS2I0I L3) to energize magnet R2 which will operate relay R2 (Fig. 7) to close switches c, d and 1 thereof and to open switches a, b and e thereof. Closing switch R2 establishes a circuit (L4R2 I0Il R2I02C6I03 L3) and a circuit (L4- R2 I00-R2 --I04 -C2 I05 -L3) to keep magnet R2 energized.

Closing switch R21 establishes three circuits (L4--RI2-I I0 RI I I I -RZ i Ili -L3) L3) to energize magnets RI2, R22 and R32 RI2, R22 and 1232 to wires m H3 and 5 4 respectively to keep magnets RI 2", R22 and R32 energized should switches RAE-R3 and R4 open.

Relays R2 and R5 having been raised as explained above, raising relays'RI2, R22 and R32 establishes, as shown in Fig. 10, a circuit (L4C2-'-'I4 *R2 15-.' RI2 -'I6*R22' net C2 which will raise contactor C2 (Fig. 6) to close switches a, b and'e thereof and to open switches c and 11 thereof. Closing switches C2 and C2 causes solenoid S2 to be energized and open valve V2 (Fig. 3). Closing switch 02 establishes, as shown in Fig. 10, a circuit (L4C5 R5 8IC2 82-C5-83L3) to energize magnet C5 which will raise contactor C5 (Fig. 6) to open switch 0 thereof and to close switches a, b, and (1 thereof. 3

Opening switch C5 prevents magnet Cli from being energized if and when limit switch LS6 closes during the down stroke of platen I0. (3105- ing switch 05 establishes a circuit (L4C5 C5' -86-LSI3 L823 LS33LS43-8I-82 C683L3) to keep magnet C5 energized. Closing switches C5 and C5 causes solenoid S5 (Fig. 6) to be energized and operate pilot valve 40 (Fig. 3) to cause slide block 23 of pump 20 to be shifted toward the left from its neutral position and liquid from pump 20 to flow through channel 22, valve V2 and channel 6 I to the head end of motor M2 and cause it to advance table 2, the speed of slide block being limited by choke 39 so that the displacement of pump 20 is gradually increased from zero with the result that table 2 is started slowly and gradually accelerated to full speed as previously explained.

It has been assumed that starting switches SS4, SSI and SS3 were successively closed shortly after starting switch SS2 was closed. Closing switch SS4 establishes, as shown in Fig. 9, a circuit (L4R4- I llIl-SS4 I 0 I L8) to energize magnet R4 which will raise relay R4 (Fig. 7) to k open switches a, b and e thereof and to close circuit through magnet R32 is maintained through switch R32 Closing switch R4 establishes two circuits (L4--R4 I0IlR4 III2 when switch SS4 opens.

Closing switch R4 establishes, as shown in Fig. 9, two circuits (L4RI4"--l I0--RI -I I I R4 II8L3) and (L4R34 II4R3 I I5 -R4 --II6-L3) to energize magnets RI4 and R34 which will operate relays RI4 and R34 to close the switches a and 17 thereof. Closing switches RI l and R34 connects magnets RI4 and R34 to wires II I and I I 5, respectively, to keep those magnets energized. Closing switch R4? will not cause magnet R24 to be energized for the reason that switch R2 is open and, consequently, relay R24 will not be raised and contactor magnet C4 will not be energized as thecircuit therethrough is broken at switch R24 as shown in Fig. 10. Since magnet C4 cannot be energized and operate contactor C4, solenoid S4 will not be energized and table 4 cannot be advanced.

Closing starting switch SSI will establish, as shown in Fig. 9, a circuit (L4--RI --I0Il-SSI IOIL3) to energize magnet RI which will raise relay RI (Fig. 7) to open switches a, b and e thereof and to close switches a, d and f thereof.

Opening switches Rl and RP has no effect as the circuits through magnets Rl2 and R are maintained by switches Ri2 and RN respectively. Opening switch RI prevents magnet and R and, consequently, relays RH and R31 will not be raised and contactor magnet Ci will not be energized as the circuit therethrough is broken at switches RI I and R3. Since magnet Ci cannot be'energized and operate contactor Cl, solenoid SI will not-be energized and table i cannot be advanced.

Closing starting switch SS3 will establish, as shown in Fig. 9, a'circuit (L@-'R3 --l0il -SS3 l0 l L3) to energize magnet RS which will raise 14 84, limit switch LS5, wire 85, limit switch L824, the starting solenoid (not shown) of thepress operating circuit to line L4, thereby causing platen ill to descend, perform a pressing operation upon the work on table 2 and then return to and stop in its initial position.

As platen i0 starts downward, limit switch LS5 opens and cuts the starting solenoid out of the table control circuit so that it may be controlled by the press operating circuit. Limit switch LS6 is not operated electrically during the down stroke of platen I ll but it is closed momentarily during relay R3 to open switches a, b and e thereof and to close switches c, d and f thereof. Opening switches R3 R3 and R3 has no effect as the circuits through magnets R2, R22 and R3$ are maintained by switches R2 l ,R22 and Rfit respectively.

Closing switch R3 establishes two circuits (R3 iilii R3* lil2 C6 W -L3) and magnet R3 energized. Closing switch R3 will have no effect for the reason that switches Ri R2 and Rl are open and, consequently, solenoid S3 cannot be energized to cause table 3 to advance.

the up stroke thereof.

Closing limit switch LS6 establishes a circuit (L4C6 -90C5-93LS6-92-L3) to energize magnet. C6 which will raise contactor C6 to open switches c, d, e, ,f and g thereof and to close switches a, b and h thereof.

Opening switch 06 has no effect as the circuit therethrough was broken when limit switches LS23 and LSM opened. Opening switches C6, C6 and C6 has no effect as the circuits through magnets RI R3 and R4 are maintained by switches Ci C3 and CM respectively. Opening switch 06 breaks the circuit through magnet R2 which permits relay R2 to drop and close switches a, b and e thereof and to open switches c, d and f thereof. 4

Opening switches R2 and R2 has no efiect as the circuits therethrough were previously broken. Opening switch R2 breaks the circuits through magnets Rl2, R22 and R32 to deenergize them and permit relays Ri2, R22 and R32 to drop which has no effect as the circuit -controlled thereby was broken when relay R5 dropped.

Closing switches R2 and R2 establishes two circuits (Lt Ri ll lil-R2**i i iR-i i i8- L3) and (Le --R23;- l'l2 -R2 -i IS -i la RZ -LS) to energize magnets RH and R23 It is therefore obvious that, after one starting switch has been closed to initiate a circuit to effect an advance movement of the table controlled by that switch, advance movement of any of the other tables is prevented.

As table 2 starts to advance, limit switch LS2! operates to break the circuit through magnet R5 and to connect wire 72 to wire 13 to establish a new circuit through magnet CZR Breaking the circuit through magnet R5 causes relay R5 to drop and break the previously established circuit through magnet C2 but limit switch LS2i has overlapping contacts and establishes the new circuit before the previous circuit is broken so that'magnet C2 remains energized. Dropping relay Rfi also breaks one of thecircuits through magnet C5 but the magnet is kept energized by the holding circuit extending through switch Ct As table 2 moves forward, it will close limit switch LS22, which will have no effect at this time, and table 2 will continue forward at high which will raise relays RH and R23 and establish holding circuits through these magnets but raising relays RH and R23 has no effect at this time as relays RSI, RH? and R33 have not been raised.

Closing switch R2 establishes a circuit (Lt- R24i I 2R2 l'l3-Rt -i IBL3) to energize magnet RM which will raise relay R25 and establish a holding circuit through magnet R2t but raising relay R26 will have no effect until relay R5 is raised.

It has previously been stated that raising contactor C6 closed switches a, b and h thereof. Closing switch C6 establishes a circuit (Le-CE .06 energized when limit switch LS6 opens as it is 'closed only momentarily. Closing switches C6 and C6 causes solenoid S6 (Fig. '6) to be energized and operate pilot valve (FIG. 3) to cause slide block 23 of pump 20 to be shifted toward the right from its near neutral position and liquid from pump 20 to flow through channel 2 I difierential valve 63 and channel 65 to the rod end of motor M2 and cause it to retract table 2, the speed of slide block 23 being limited by choke 39 so that the displacement of pump 20 is gradually increased withthe result that table 2 is started slowly and gradually accelerated to full speed as previously explained. 1

As table 2 moves outward, it will permit limit switch L826 to return to its initial position, then it will operate limit switch L823 to its initial position and it will continue to move outward at high speed until it opens limit switch L522 to break the-circuit through magnet Cii which'will permit contactor C6 to drop and deenergize solenoid se to permit plunger M of pilot valve it to be returned to its neutral position to cause the displacement of pump 28 to be gradually reduced and thereby cause table 2 to be gradually decelerated as previously explained.

When table 2 reaches its outer limit; it operates limit switch LSZI to its initial position, thereby breaking the circuit through magnet C2 which will permit contactor C2 to drop and open its switches a, b and e and close its switches c and d.

Opening switch C2 has no effect but opening switches C2 and C2 deenergizes solenoid S2 C2 and the return of switch LS2! to its initial position re-establishes, as shown in Fig. 10, the circuit (L4 R -94-C4-9i5-C396C2- 37C|98LSII--LS2ILS3II.S4IL3) to energize magnet R5 which raises relay R5.

If non of theother starting switches had been closed, the drive would now come to rest and remain idle until a starting switch was closed but it has been assumed that starting switches SS4, SSI and SS3 were closed in succession after switch SS2 was closed, and the closing of switches SS4, SSI and SS3 caused certain circuits to be set up as explained above.

Therefore, since relays R4, RI4, R24 and R34 have been raised due to the establishing of circuits as a result of closing switch SS4, raising relay R5 will establish, as shown in Fig. 10, a circuit (L4 C4 I4 R4 RI 4 -I6--R24 1'|R34'I8- -R5 19L3) to energize magnet 04 which will raise contactor C4 to energize solenoid S4 and to deenergize magnet R5 thereby causing table 4 to be advanced and retracted in the same manner that table 2 was advanced and retracted and causing relay R5 to drop.

The electric circuits for controlling the four tables function in the same manner and are substantially identical, contactors C5 and C6 and relay R5 being common to all four circuits.

When contactor C6 is raised in response to operation of limit switch LS5 during upward movement of platen III as explained above, it causes relays R4, RI4, R24 and R34 to drop for the same reason that relays R2, RI2, R22 and R32 dropped during operation of table 2.

Dropping relay R4 establishes, as shown in Fig. 9, two circuits (L4R3I-I I4R4*I I 5RI' R3 I Ni -L3) to energize magnets R3I and R33 which will raise relays R3 Ii and R33 and establish holding circuits through these magnets but raising relays R3I and-R33 has no eflect at this time as relay R5 has not been raised.

When table 4 reaches its outer limit, it operates limit switch LS4I to cause contactor C4 to drop and establish, as shown in Fig. 10, a circuit (L4- R5 94C495C395C2 =-9l-CI ISI I--LS2 I-LS3 ILS4IL3) to ener ize magnet R5 which will raise relay R5 and establish through switch R5 a holding circuit for magnet R5 If none of the starting switches had been closed after switch SS4 was closed, the drive would now come to rest and would remain idle until a starting switch was closed but it has been assumed that switches SSI and SS3 were closed in succession after switch SS4 was closed, and the closing of switches SSI and SS3 caused certain circuits to be set up as explained above.

Therefore, since relays RI I, 122i and R3! have been raised due to the establishing of circuits as the result of closing switch SSI raising relay R5 will establish, as shown in Fig. 10, a circuit (L4- *which permits control valve V2 toclose. Closing switch C2 has no effect but the closing of switch a 16 Cl I'4-Rl-15-RIl -'l6-R2I l|-R3I 18R5 -79L3) to energize magnet CI which will raise contactor Cl to energize solenoid Si and to deenergize magnet R5 thereby causing table I to be advanced and retracted in the same manner that tables 2 and 4 were advanced and retracted and causing relay R5 to drop. 4

When contactor C6 is raised in response to operation of switch LSS during upward movement of platen I I3, it causes relays Rl, Rl I, R2l and R3! to drop for the same reason that relays R2, RI2, R22 and R32 dropped during operation of table 2. Dropping relay RI establishes, as shown in Fig. 9, a circuit (L4RI3-I lIl RI --l I I --R3 I ii-L3) to energize magnet RI3 which will raise relay RI3 and establish a holding circuit through that magnet but raising relay RI 3 will have no eiiect until relay R5 is raised.

When table I reaches its outer limit, it operates switch LSI I to cause contactor C! to drop and establish, as shown in Fig. 10, a circuit (L4R5 94 C4 95 C3 96 C291Cl98- LSI ILS2lLS3ILS4l-L3) to energize magnet R5 which will raise relay R5 and establish through switch R5 a holding circuit in magnet R5.

Since starting switch SS3 was closed after switch SSI was closed and since relays R3, RI3, R23 and R33 have been raised as explained above, raising relay R5 will establish, as shown in Fig. 10, a circuit (L4--C3 -l4 --R315 RI3 lli R23'*ll --R33* '!8 R5 19 L3) to energize magnet C3which will raise contactor C3 to energize solenoid S3 and to deenergize magnet R5 thereby causing table 3 to be advanced and retracted in the same manner that tables 2, 4 and I were advanced and retracted and causing relay R5 to drop.

When contactor C6 is raised in response to operation of switch LS6 during upward movement of platen l0, it causes relays R3, RI3, R23 and R33 to drop for the same reason that relays R2, Rl2, R22 and R32 dropped during operation of table 2.

When table 3 reaches its outer limit, it operates limit switch LS3! to re-establish the circuit through magnet R5 which will raise relay R5 and If it is desired to retract a table after'it has started to advance, it is simply necessary to close the reversing switch RSI, RS2, RS3 or RS4 associated with that table to establish a circuit from line L3 through the reversing switch, wire 89, limit switches LS44, LS34, LS24 and LSI4, wire 88 and magnet C6 to line L4 to energize magnet G6 which will raise contactor C6 to effect re-. versal of pump 20 and consequently retraction of the table but, if the reversing switch is closed after the table is fully advanced and has opened limit switch L814, LS24, LS34 or LS44, the. table will not be retracted for the reason that the cir cuit through magnet C6 is broken by the ope limit switch.

From the foregoing, it will be obvious that the tables will be operated in the order in which the starting switches are closed, that any table may 17 be operated a plurality of times beforeanother table is operated and that the number of tables or other elements may .be varied by simply vary ing the number of circuits.

The drive shown and described herein is susceptible of various modifications and adaptations without departing from the scope of the invention which is hereby claimed as follows:

1. In a machine having a plurality of tables, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said fully advanced for efiecting operation of said.

motors, a starting means associated with each motor and operable to efiect operation of said valve means to cause the motor associated with that starting mean to advance the table connected thereto, the several starting means bein operable in any desired sequence, means responsive to any table being fully advanced for efiecting operation of said valve means to reverse the flow in said circuit andthereby cause the motor connected to that table to retract the same, and means responsive to any table being fully retracted for efiecting operation of said valve means to cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence.

2. In a machine having a plurality of tables. the combination of a hydraulic motor connected to each table to advance and retract the same, a. pump, fluid channels connecting said motors to said pump and forming therewith a' hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to eflect operation of said valve means to cause the motor associated with that starting means to advance the table connected thereto, the several starting means being operable in any desired sequence, means for causing the speed of the advancing table-to be gradually increased from zero to maximum, means responsive to a table being advanced to a given point for causing said table to be gradually decelerated, means responsive to any table being fully advanced for effecting operation of said valve means to reverse the flow in said "circuit and thereby cause the motor connected to that table to retract the same, and means responsive to any table being fully retracted-for efiecting operation of said valve means to cause an advance movement of the table connected to the motor the starting-means of which was next operated in said sequence.

3. In a machine having a plurality of tables,

the combination of a hydraulic motor connected to each table to advance and retract the same,

a pump, fluid channels connecting said motors.

to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to eifect operation of said valve means to cause the motor associated with that starting means to advance the table connected thereto, the several starting means being operable in any desired sequence, means for causing the speed of the advancing table to be gradually increased from zero to maximum, means responsive to a table beingadvanced to a given point for causing said table to be gradually decelerated, means responsive to' any table being meansfor causing the speed of the advancing connected to the motor-the starting means of which was next operated in said sequence.

4. In a machine having a plurality of tables, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to efiect operation'of said valve means to cause the motor associated with that starting. means to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any one table starting to advance for preventing any other table from advancing until after said one table has been fully retracted, means responsive to any table being .fully ad- 'vanced for effecting operation of said valve means said valve means to cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence. 4

5. In a machine having a plurality of tables, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said'motors to said pump and forming therewith a hydraulic circuit, Valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to efiect operation of said .valve means to cause the motor associated with that starting means to advance the table conpreventing any other table from. advancing until after said one table has been fully retracted,

table to be gradually increased from zero to maximum, means responsive to a table being advanced to a given point for causing said table to be gradually decelerated, means responsive to any table being fully advanced for effecting operation of said valve means to reverse the fi ow in said circuit and thereby cause the motor connected to that table to retract the same, means for causing the speed of the retracting table to be gradually increased from zero to maximum, means responsive to a table being retracted to a given point for causing said table to be gradually decelerated, and means responsive to any table being fully retracted for effecting operation of said valve means to cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence.

6. In a machine having 'a plurality oftables,

' the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, fiow control means for controlling the flow in said circuit, valve'means for controlling each of said motors, and a control for controlling said control means and including a starting means for each motor operation of which effects operation of said flow control means and the valve means for controlling the same motor to cause said motor to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any table being fully advanced for effecting operation of said flow control means to reverse the flow in said circuit and thereby cause the motor connected to that table to retract the same, and means responsive to any table being fully retracted for efiecting operation of said flow control means and the valve means for controlling the motor the starting means of which was next operated in said sequence to thereby cause that motor to advance, the table connected thereto. r l

'7. In a machine having a plurality of tables, the combination of a hydraulic motor connected to each table to advance and retract the same. a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, flow control means for controlling the flow in said circuit, valve means for controlling each of said motors, and a, control for controlling said control means and including a starting means for each motor operation of which effects operation of said flow control means and the valve means, for controlling the same motor to cause said motor to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any one table starting to advance for preventing any other table from advancing until after said one table has been fully retracted, means responsive to any table being fully advanced for effecting operation of said flow control means to reverse the flow in said circuit and thereby cause the moi or connected to that table to retract the same, and means responsive toany table being fully retracted for efiecting operation of said flow control means and the valve means for controlling the motor the starting said control means and including a starting means for each motor operation of which efiects opera-- tion of said flow control means and the valve said control means and including a starting mean means for controlling the same: motor to cause said motor to advance the table connected thereto, the several starting means being operable in any desired sequence, means for causing the speed of the advancing table to be gradually increased from zero to maximum, means responsive to a table being advanced to a given point for causing said table to be gradually decelerated, means responsive to any table being fully advanced for efiecting operation of said flow control means to reverse the flow in said circuit and thereby cause the motor connected to that table to retract the same, and means responsive to any table being fully retracted for efiecting operation of said flow control means and the valve means for controlling the motor the starting means of which was next operated in said sequence to thereby cause that motor to advance the table connected thereto. r

9. In a machine having a plurality of tables, the combination of a hydraulic motor connected to each table to advance and retract the same, a

pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, flow control means for controlling the flow in'said circuit, valve means for controlling each of said motors, and a control for controlling for each motor operation of which effects operation of said flow control means and the valve means for controlling the same motor to cause said motor to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any one table starting to advance for preventing any other table from advancing until after said one table has been fully retracted, means for causing the speed of the advancing table to be grad-,

ually increased from zero to maximum, means responsive to a table being advanced to a given point for causing said table to be gradually decelerated, means responsive to any table being fully advanced for effecting operation of said flow control means to reverse the flow in said circuit and thereby cause the motor connected to that table to retract the same, means for causing the speed of the retracting table to be gradually increased from zero to maximum, means responsive to a table being retracted to a given point for causing said table to be gradually decelerated and means responsive to any table being fully retracted for effecting operation of said flow control means and the valve means for controlling the motor the starting means of which was next operated in said sequence to thereby cause'that motor to advance the table connected thereto.

10. In a press having a platen, power means for reciprocating said platen, a control adapted when actuated to cause said power means to advance and retract said plates, and a plurality of tables each of which is adapted to be advanced into and retracted from the path of said platen, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to efiect operation of said valve means to cause the motor associated with that starting means to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any one table being fully advanced for actuating said press control to thereby cause said platen to be advanced and retracted, means responsive to said platen being retracted for eflecting operation of said valve means to reverse the flow in'said circuit and thereby cause the motor connected to said one table to retract the same, and means responsive to any table being fully retracted for effecting operation of said-valve means to cause an advance movement of the table connected to the motor the starting means or which was next operated in said sequence.

11. In a press having a platen, power means for reciprocating said platen, a control adapted when actuated to cause said power means to advance and retract said platen, and aplurality of tables each of which is adapted to be advanced into and retracted from the path of said platen, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to effect operation of said valve means to cause the motor associated with that thereby cause said platen to be advanced and retracted, means responsive to said platen being retracted for efiecting operation of said valve means to reverse the flow in said circuit and thereby cause the motor connected to said one table to retract the same, and means responsive to any table being fully retracted for effecting.

operation of said valve means to cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence.

12. In a press having a platen, power means for reciprocating said platen, a control adapted when actuated to cause said power means to advance and retract said platen, and a plurality of tables each of which is adapted to be advanced into and retracted from the path of said platen, the combination of a hydraulic motor connected to each table to advance and retract the same, a pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, valve means for controlling the flow in said circuit and the operation of each of said motors, a starting means associated with each motor and operable to effect operation of said valve means to cause the motor associated with that starting means to advance the table connected thereto, the several starting means being operable in any desired sequence, means responsive to any one table starting to advance for preventing any other table from advancing until after said one table has been fully retracted,

table to be gradually increased from zero to maximum, means responsive to a table being ad-- vanced to a given point for causing said table to be gradually decelerated, means responsive to any one table being fully advanced for actuating said press control to thereby cause said platen to be advanced and retracted, means responsive to said platen being retracted for efiecting operation of said valve means to reverse the fiow in said circuit and thereby cause the motor connected to said one table to retract the same, means for causing the speed of the retracting table to be gradually increased from zero to maximum, means responsive to a table being retracted to a given point for causing said table to be gradually decelerated, and means responsive, to any table being fully retracted for eflc'ecting operation of said valve meansto cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence.

13, In a press having a platen, power means for reciprocating said platen, a control adapted when actuated to cause said power means to advance and retract said platen, and a plurality of tables each of which is adapted to be advanced into and retracted from the path of said platen, the combination of a hydraulic motor connected to each table to advance and retract the same, a reversible variable delivery pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, a pump control for causing said pump to deliver liquid into either side of said circuit and for varying pump delivery between zero and a maximum,]

valve means for controlling each of said motors, a starting means for each motor operation of which efiects operation of said pump control and the valve means for controlling the same, motor to cause said pump to deliver liquid to that motor and enable it to advance the table connected thereto, the several starting means being oper-' able in any desired sequence, means responsive to any one table being advanced for efiecting operation of said pump control to. cause pump delivery to be reduced approximately to zero, means responsive to any one table being fully advanced v for actuating said press control to thereby cause said platen to be advanced and retracted, means responsive to said platen being retracted for effecting operation of said pump control to reverse the flow in said circuit and thereby cause the mo tor connected to said one table't'o retract the same, and means responsive to any table-being fully retracted for effecting operation of said pump control and said valve means to cause an advance movement of the table connected to the motor the starting means of which was next operated in said sequence.

14. In a press having a platen, power means for reciprocating said platen, a control adapted when actuated to cause said. power means to advance and retract said platen, and a plurality of tables each of which is adapted to be advanced into and retracted from the path of said platen, the combination of a hydraulic motor connected to each table to advance and retract the same, a reversible variable delivery pump, fluid channels connecting said motors to said pump and forming therewith a hydraulic circuit, a pump control for causing said pump to deliver liquid into either side of said circuit and for varying pump delivery between zero and a maximum, valve means for controlling each of said motors, a starting means for each motor operation of which efiects operation of said pump control and the valve means for controlling the same motor to cause said pump to deliver liquid to that motor and enable it to "advance the table connected thereto, the several starting means being operable in any desired sequence, means esponsive to any one table starting to advance for preventing an. other table the flow in said circuit and thereby cause the motor connected to said one table to retract the same, and means responsive to any table ,being full-y retracted for effecting operation of said ments and adapted when energized to drive it.

inoppositfe directions, a power source for enersizing said motors, means for controlling the delivery of energy to said motors including a separate controller for each motor, and an electric circuit having instrumentalities for operating said control means and including a starting switch for each element and adapted when operated to initiate a circuit to efiect operation of said control means to cause movement in one direction of the element with which that switch is associated, a plurality of switch means' each of which is operable by. one of said elements at a given point in the movement thereof in said direction and adapted when operated to initiate a circuit for operating said control means to efiect movement of that element in the opposite direction, a plurality of limit switches each of which is operable lishing a circuit to effect operationof any one of the other elements whose starting switch was operated next after the element operating said one limit switch had started to move.

16. A hydraulic drive, comprising a plurality of hydraulic motors, a source of motive liquid, fluid channels connecting said motors to said source in parallel with each other and forming therewith a hydraulic circuit, flow control means for directing liquid from said source into either or neither side of said circuit, valve means for controlling each of said motors, and an electric circuit having instrumentalities for operating said means and including a plurality of sub-circuits, a-

plurality of starting switches each of which is associated with one of said motors and adapted when operated to initiate energlzation of a subcircuit to eifect operation of said flow control means and the valve means for controlling the motor with which the operated starting switch I is associated to thereby cause that motorto opcrate in one direction, a plurality of switch means each of which is operable by one of said motors duringoperation thereof in said direction and which when operated is adapted to initiate energization of a. sub-circuit to effect op n of saidnow control means to therebycause that motor to operate in the opposite direction, a plurality of limit switches each of which is operable y one of said motors at the completion or its operation in said opposite direction, means responsive to initiating operation of any one moand means responsive to operation or any one of 24 said limit switches for energizing asub-circuit to efiect operation of any one of the other motors whose starting switch was operated next after the motor operating said one limit switch had started to operate.

17. In a system having a plurality of individually movable elements, the combination of a plurality of motors each of which is connected to one of said elements and adapted when energized to operate the same, means for energizing said motors, control means for said motors in-.

cluding a separate controller for each motor, a starting means associated with each motor and operable to effect operation of said control means to cause the associated motor to operate the element. connected thereto, theseveral starting means being operable in any desired sequence, means responsive to one element starting to opcrate for preventing any other element from being operated, and means responsive to an element completing its operation for eiiecting operation of another of said motors the starting means of which was next operated in said sequence.

18. In a system having a plurality of individually movable elements, the combination of a pluralityof motors each of which is connected to one of said elements and adapted when energized to operate the same,-means for energizing said motors, control means for said motors including a separate controller for each motor, a starting means associated with 'each motor and operable to efl'ect operation of said control means to cause the associated motor to operate the element connected thereto, the several starting means being operable in any desired sequence, means respon sive to one element starting to operate for preventing any other element from being operated, means-for gradually accelerating and decelerating each of said motors, and means responsive to an element completing its operation for effecting operation of another of said motors the starting means of which was next operated in said sequence.

1 19. In a system having a plurality of individually vmovable elements, the combination of a plurality of hydraulic motors each of which is connected to one of said elements and adapted when energized to operate the same, means for and means responsive .to an element completing its operation for effecting operation of another of said motors the starting switch of which was next operated in said sequence.

20'. In a machine having a plurality of individually movable elements, a plurality of motors each of whichis connected to one of said elements and adapted when energized to move it through a given cycle, and means for energizing said moto'rathe combination of means for controllin the delivery of energy to said motors including a separate controller for each motor, and interlocking electric circuits having devices for operating said control means and including a starting switch associated with each element and adapted when operated to establish a circuit to efiect operation of said control means to initiate movement of the element with which that switch is associated, a plurality of limit switches each of which is operable by one of said elements at the end of its cycle of movement, means responsive to the initial movement of any one element for preventing .the subsequent operation of a starting switch from causing movement of any other 10 aemeee element until after said one element 11 reached the end of its cycle of movement, and means responsive to operation of any one of said limit switches for establishing a circuit to effect movement of any other element whose starting switch was operated next after the switch associated with the element operating said one limit switch was operated.

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